I removed the argument --ignore-environment from the action's invocations of nix develop. I haven't found any benefit from it, and it created surprising annoyance to anyone using https://devenv.sh in a flake. The effect was errors with messages like mktemp: command not found, mkdir: command not found, etc. The workaround was to add --keep PATH to the arguments. But how would people figure that out?!
Anyone who does want to --ignore-environment can of course add that to their arguments: instead.
Full Changelog: v1.0.0...v1.1.0